Python 3 almost killed Python.
It's normal. Once a community loses faith, it's hard to stop them from leaving.
People were being crybabies; the critics were extremely vocal and few. Python 3 improved the language in every way and the tooling to upgrade remains unmatched.
Organizations struggled with it but they struggle with basically every breaking change. I was on the tooling team that helped an organization handle the transition of about 5 million lines of data science code from python 2.7 to 3.2. We also had to handle other breaking changes like airflow upgrades, spark 2->3, intel->amd->graviton.
At that scale all those changes are a big deal. Heck even the pickle protocol change in Python 3.8 was a big deal for us. I wouldn't characterize the python 2->3 transition as a significantly bigger deal than some of the others. In many ways it was easier because so much hay was made about it there was a lot of knowledge and tooling.